136 NORTH AMERICAN FAUNA. [v0. 16. 
nists who kindly determined special species or special genera are Mrs. 
N. L. Britton, Mr. Frederick V. Coville, Prof. W. Rk. Dudley, Mr. M. L. 
Fernald, Mr. John B. Leiberg, Mr. C. L. Pollard, Dr. B. L. Robinson, 
Dr. J. N. Rose, Prof. P. A. Rydberg, Mr. J. K. Small, and Prof. Wil- 
liam Trelease. In order to properly place the credit for this assistance, 
the botanist responsible for the identification is in each instance men- 
tioned. Where no one is named I am personally responsible. 
A few mosses and ferns were found in the timberline region of 
Shasta. The mosses, kindly determined by Mrs. Britton, are Har- 
pidium (2 crannulatum Gumb.), Auldcomnium androgynum Sch., and a 
species of Philonotis. They are contined rather closely to the borders 
of the alpine streams, where the Aulacomnium forms compact mats of 
a yellowish color. 
The ferns have been determined by Mr. William R. Maxon through 
the courtesy ot Mr. Frederick V. Coville, curator of the National Her- 
barium. The species which grow sparingly ‘n the heather meadows and 
under the edges of rocks near timberline are: Pryvpteris aculeata scopu- 
ina (Eaton), Cystopteris fragilis (L.) Beruh., Cheilanthes gracillima 
D.C. Katon, Cryptogramme acrostichoides R. Br., and Phegopteris alpes- 
tris (Hoppe) Mett. Much lower down, along the boundary between 
the Canadian and Transition zones, Pteris aquilina lanuginosa (Bory) 
Hooker, and Asplenium filirfeemina (L.) Bernh. oceur, The brake 
(Pteris)is very abundant on the pumice sand at Wagon Camp and 
Sisson and wherever there is sufficient moisture in the soil in spriug 
and early summer. The black-beard lichen (:Llectoria Jremonti) and the 
handsome yellow tree lichen (Hrernia vulpina) abound in the dark forest 
of Shasta firs. 
In the chapter on ‘Life Zones’ the more distinctive species have 
been grouped according to their vertical distribution (see pp. 52-68), but 
for convenience in finding the notes relating to particular species, 
they are here arranged in systematic order. Jn the case of certain 
plants tound by us only on the borderland between adjacent zones, the 
zone position is in doubt and must be determined by future study. 
The most important kinds of plants from the standpoint of geo- 
graphic distribution are naturally those that remain longest in a par- 
ticular spot. Hence, as pointed out by Coville,' trees, shrubs, and 
perennials are the kinds most useful in determining zone boundaries. 
For this reason little attention is here given to annuals. 
Pinus monticola Douglas. Silver Pine; Mountain White Pine. 
Common in places, chiefly in the upper half of the Canadian zone, 
but local and by no means generally distributed. Wherever it oceurs 
it is mixed with Shasta firs, and in places it reaches up high enough to 
overlap the lower edge of the black alpine hemlocks and white-bark 
timberline pines. (See p. 38.) 
' Botany of Death Valley Expedition, pp. 17-18, 1893. 
